“Tapping” is a cutting process in which a tap is rotated into a starting hole in a workpiece. The workpiece is usually metal, and the starting hole is usually slightly larger than the thread root diameter. The tap has threads formed thereon in a configuration corresponding to the threads to be cut in the workpiece. It is fluted to form cutting edges and provide for chip clearance. In workshop environments, when the starting hole is to be tapped, the tap is usually held in a tap wrench and is manually rotated while it is pressed into the starting hole. The tap must be started axially into the starting hole. The front, entry end of the tap is tapered so that the full cut of the threads is not taken by the first tap threads. This permits entry of the tap into the starting hole. The tap is rotated in the clockwise direction (for right-hand threads) and is pressed into the starting hole at the same time, which requires care and dexterity.
After chip cutting is started and chips are forming, it is desirable to rotate the tap in the unscrewing direction to break loose the cut chips. When there are four flutes on the tap, it is desirable to advance the tap in the cutting direction more than half a turn and then back and out more than a quarter turn. In workshop environments, tapping has previously been done by hand. It is desirable to provide a hand-held powered tap driver for an artisan or a workman. The hand-held powered tap driver should be light and easy to handle so that an artisan can easily and quickly create tapped holes.